Method and apparatus fob mixing solid materials with liquids



0. D. CUNNINGHAM.

METHOD AND APPARATUS FOR MIXING SOLID MATERIALS WITH LIQUIDS. lAPPLICATION FILED AUG.21.1920.

j avwantoz `UNITED STATES 'PATENT OFFICE.

onnv n. cnnnrnenainorBUFFALO,,new Yoan, A'ssrenonj iro na'rIoNAn ANILINE a CHEMICAL couteaux, Inc., or new YORK, n. Y., A conroaarrron or NEW YORK.'

lunrnon AND arranarns son nimmer SOLID' Marnier-ALS.l WITH LIQUIDS.

Specification of Letters Patent.

rat-eaten July 11, 1922;.

l.9.1115lcaton filed August 21, 1920. Serial IiTo. 405,198.

Tocllwiom it may concern:

Be it known that I, ORIN D. CUNNInG- HAM, a citizen of the United States, residing at Bnlialo, in the coun-ty oitv Erie, State `of New. York, have invented certain new and useful improvements in Methods and Apparatus for Mixing Solid Materials with Liquids; and I do hereby declare the following to be a full,.clear, and exact descripion of the invention, such as will. enable others skilled in the art towhich it appertains to make and use the same. This invention relates to an improved method and apparatus for mixing solid materials with liquids,` and` more particularly for mixing light powderednnaterial with a heavy viscous liquid at a low temperature. The invention. is of special value in effecting the mixture of afpowdered material with a heavy viscous liquidsuch `as concentrated sulfuric acid, where reaction takes V.place with evolution of heat, and where it is important to maintain a low temperature and vigorous agitation during the interinixture and reaction. 'v

Where a solid material, in a powdered form, is to be added to a heavy liquid, such as concentrated sulfuric acid, and where it is important to maintain vigorous agitation of the mixture and suliicient cooling thereof to maintain a lowtemperature, and especially where the solid reacts with thel liquid n with the evolution of heat, it is difficultto obtain the :necessary vigorous agitation coinbined with the necessary coolingeffect. If brine coils are used for keeping the mixture cold, they inhibit the necessary vigorous agitation. I

The present invention overcomes the difficulty of apparatus heretofore employed, in which an agitator and brine coils are provided in the same receptacle; and the pres ent invention provides an improved agitation and cooling method and apparatus well' adapted for bringing about the desired-.iw timacy ol' intermixture of the solids with liquids. even where the solid is a light pow-VV der and the liquid a heavy viscous liquid, and for bringing about effective cooling of the mixture. l i

According to the present invention, the agitation and the cooling are effected in separate parts of the apparatus, whlch separate parts are so interconnected, and so coacti, that the desired intermixture, agitation and coolingwill talre place in a rapidland continuous manner. Y

The improvedapparatus of the invention thus hasa receptacle or reservoir provided with a' cooling jacket and cooling coils for securing the necessary-cooling effect, and a separate mixing and agitating compartment, to which the solid is supplied andin which vigorous agitation and admixture takes place; while the cooling and agitating coinpartments or receptacles are so' connected that the agitatedjlmixture is continuously.

forced into the` cooling compartment, while the cooled liquid or mixture is continuously returned from Ythe cooling'compartment to themixing compartment for further admix ture of the solid material therewith.

The `imprpved process of the invention involves, the continuous admixture of the solid and liquid, the continuous discharge of the y agitated mixture intothe cooling compartment, with resulting cooling thereof to the desired degree, and the return of the cold mixture to the mixing and agitating com-` partment forthe further addition and admixture of the solid material; so that the solid is progressively added and admixed, and the mixture continuously cooled, until the complete admixture and reaction has taken place. Y y

l The invention is applicable to the admixture and treatment of various materials, and especially lthe treatment of solid materials with concentrated sulfuric acid, where the solid ,materials react with the sulfuric acid with evolution of heat Vof reaction, and where it is important to maintain a low tem- Y perature during-the admixture and reaction.

The invention Iwill'be further described in connection with `the accompanying drawing illustrating one embodiment thereof in a somewhat conventional and diagrammatic iinanner. The nature and object'of the invention, as well as its advantages, will more fully appear` from the following more detailed description.

The apparatus illustrated in the accompanying drawing comprises a reservoir or re- Y ceptacle l equipped with a brine coil or coils Qand having a brine jacket 3. This reservoir or receptacle is adapted to contain the main body of the liquid, with which the solid is to be admixed. Alseparate chamber vor compartment l is provided having therein a suitable agitator 5, shown as a V-shaped agi- .tator closely fitting the sides of the coneshaped bottom of the compartment.v The compartment 4 has a cooling jacket 6 connected with the cooling jacket of the receptacle 1; by a A.connecting pipe, 7. The brine or other cooling agent enters through the supply pipe 8, passes throu h the jacket 3, then through the pipe 7 tot e jacket 6, and iinally discharges through the pipe 9; orsthe How of brine can be reversed, entering at 9 and leaving at 8. The mixing-compartment 4 is connected with the compartment 1 by va large pipe 10 having a regulating valve 11 therein. The ibottom of the mixing compartment 4 is connected with Va centrifu al pump 12 which in turn is connected with t e bottom of the compartment 1 through the pipe 13 and the branch pipe14 having regulating valve 15 therein. The pipe 13 has an its upward discharge.

extension 16 having a regulating valve 17 therein, this extension being arranged to permit drawing off of the liquid mixture at the end -of the mixing or reaction operation. Allt will be'noted that the pipe 14 is connected-with the receptacle l at a point remote from'the pipe 10,j so that the liquid mixture forced into the receptacle 1 through the pipe 14 will notpass directly to the outlet 10, but 4will serve tov agitate the entire body-of the liquid, owin to the velocity of thermometer may bey placed-at any desired place in the apparatus, for example, in the pipe 13, as indicated at- 18).- The pipes 13,14 and 16 are provided with a suitable insulation, such as magnesia mixture, to avoid undue warming of the mixture passing through these pipes. A deflector 19 is arranged at the outlet end of the pipe `1().todefiectthe solution downward or to one side as it enters the receptacle or compartment'4. It will be understood thatthe apparatus is made of suitable acid- 'resistant material, Where itis to be used with acid liquids, such as concentrated sulfuric acid. It willA also be understood that thel apparatus may be provided With suitable covers for closing itv during operation, as Well assuitable vfeeding devices (not shown) for supplying theli uidV and the solid in thedesired amount and at the'proper rate. Where chemical reaction takes place in theapparatus, the material of the apparatus should, of course. be `resistant to such chemical reaction.

In the operation of the apparatus, the valves 11 and 15 are closed, the reservoir 1 y is Filled about two-thirds full with the vis- -the cooling jackets and cooling coils.

to the centrifugal pump 12 and is forced back into the reservoir 1 through the pipes 13 and 14. The rate of How of the liquid is thus controlled by the valve llfand the centrifugal pump 12, and the liquid is kept in constant circulation, owing to the gravity flow from the reservoir 1 to the mixln receptacle 4, and the action ofl the centri ugal pump in returning the. liquid to the reservoir 1. The valve 15 will be kept Wide open while the valve 11 will be so adjusted that the rate of fiow of the liquid is properly regulated. The circulation of the liquid in the manner described results in rapid cooling, owing to the large cooling area provided by the cooling jackets and the cooling coil; and the liquid is thus rapidly brought to the desired low temperature.

When the desired temperature is reached, the agitator 5 is started, the rate of flow of 4theliquid is readjusted so that the coneshaped bottom of the lmixing chamber 4 is partly filled in order to enable the agitator to form a vortex by rapid rotation of the solution, and the sohd Vmaterial is then slowly added to the chamber 4, becoming instantly mixed with thecooled liquid by the agitator.. The rate of addition of the solid can be regulated to suit the conditions of the particular operation, and will depend upon various factors, such asthe heat of reaction to Ibe neutralized, the cooling effect desired, the rapidity of circulation, etc. The mixture formed in the compartment 4 is continually and rapidly transferred, after admixture, to the reservoir 1, entering through the pipe 15 Vwith considerable velocity and thereby causing agitation of the liquid in the reservoir 1. The liquid or liquid mixture Hows from this reservoir throughthe pipe 1() to the mixing compartment and the further amounts of solid are admixed therewith.

`This continuous circulation enables the solution to be thoroughly cooled before it recnters the mixing chamber 4 to receive more solid material. Where the reaction takes place with the evolution of heat, the continuous and pro ressive character of the process enables the eat of reaction to be continuously and progressively neutralized, as the solid is progressively added, and the cooling and circulation progressively take place.

When the admixture and reaction have been completed, the contents of the apparatus may be drawn off through the pipe 16. The method and apparatus of the inven` tion are well adapted for carrying out exothermic reactions in sulfuric acid where the conditions of reaction require that the reacting substances be instantaneously mixed with the acidv and the solution maintained at a low temperature. The solid may thus be of a charac-ter which combines with or:

dissolves in the acid so that the resulting mixture no longerA contains the solid in a solid state,; but contains it in solution or in the form. of reaction products. The present invention overcomes the difficulty involved in other typesV ofapparatus, heretofore used for similar: purposes, in bringingfabout. the' proper mixing of very light solids withy a heavy viscous liquid, l inasmuch `as the 'f mixing? and coolingl operations" of the present invention take place r mainly in separate chambers so connected that a rapid and rontinuous circulation from one to the other takes place. f n

It will be evident that the specific construction and arrangement of the apparatus can be varied, and the mixing and cooling chambers differently arranged, or arranged.

in different relative positions, or connected with pipes having different relative positions, so long as continuity of operation and of circulation is provided for. It will be evident also that the particular type and construction of the mixing chamber and of the agitator is capable ofvariation without departing from the spirit and scope of the invention. l

I claim:

l. The method of effecting the admixture of solids with liquids at low temperatures, which comprises circulating the liquid from and to a cooling chamber through a mixing chamber of relatively smallcapacity, admixy ing the solid with the liquid. in the mixing chamber with vigorous agitation and continuously returning thc liquidwith the admixed solid and reaction products to the cooling chamber, the rate of addition of the solid and the rate of circulation of the liquid being so regulated as to maintain the desired low temperature.

`2. The method of effecting the admixture, at a low temperature, of solids and liquids which react together with evolution of heat, which comprises 'gradually adding thesolid to the liquid in a mixing chamber ofrelatively small capacity, continuously forcing the resulting` mixture to a larger cooling chamber and subjecting it there to active cooling, and returning the cold liquid from the cooling chamber tothe mixing chamber for admixture of further amounts of solid therewith. v

3. The method of effecting the admixture of solids with liquids at low temperatures, which consists in continuously withdrawing a relatively small vportion ofl liquid from a relatively large cooled body of liquid-and in continuously returning'such smaller portion to the larger body, and in mixing the solids with such portion during'its passage from and to the relatively large body, until com- -plete admixture and reaction has vtaken place. f v

, 4. vThe method ofv effectingthe admixture of solids with liquids at low temperatures, which consists in continuously. withdrawing a relatively small portion of liquid from .a

relatively large cooled body of liquid and in continuously returning such smaller portion, and' in mixing the solids with such portion during its passage from and to the relatively largebody, untilcomplete admixturey and reaction has talreniplace, and in vigorously agitating such portion during the addition of the solids.

5. An apparatus for effecting the mixture ofsolids with liquids ata low temperature,

comprising a cooling compartment provided turning it to the cooling compartment untilcomplete admixture and reaction has taken place, and means within the mixing compartment for vigorously agitating the withdrawn portion as it passes through the compartment.`

V7. An apparatus for the instantaneous mixing of light powdered material with viscous liquids maintained at a low temperature, comprising a cooling reservoir equipped Vwith `brine coils and containing the main bodyV ofthe liquid, a mixing chamber into which the liquid from the cooling reservoir ,flows by gravity, an agitator within the mixing chamber, and a centrifugal pump connected and arranged to transfer the mixture from the mixing chamber to the reservoir.

8. An apparatus for the instantaneous mixing of light powdered materials with viscous liquids maintained at a low temperature, comprising a cooling reservoir having cooling coils and containing the main body ofthe liquid, a cone-shaped mixing chamber into which the solution from the cooling reservoir flows by gravity, means for regulating 'such How, an agitator within the mixing chamber'r which effects whirling of the .liquidA with resulting production of a vortex,

whereby the added solid material is instantaneoiisly mixed with the liquid, and a centrifugal pump connected and arranged to transfer the resulting mixture from the mixing chamber back to the cooling reservoir. 9. An Yapparatus for the instantaneous mixing of light powdered materials and viscous liquids maintained at a Vlow temperature, comprising a cooling reservoir having brine coils and adapted to contain the main body of the liquid, n' mixing chamber infto which the solution from the cooling reservoir flows by gravity, means forregulatng such flow, an yagitetorin the .mixing uhmm ber for effecting substantially instantaneous admixture of solid` `with the liquid', and

means for. transferring the result ingnnxj` ture again means .delivering atthe bottom of the reser- 10 to the cooling reservoin said bodyof the liquid therein tinuul circulation.4

In testim is kept in con- Ony whereof I aiiix myfsi nature. 15

oRIND. GUNNING '-AMV.. 

